The present invention relates to a high efficiency illuminating light source which ensures such a level of color reproduction that allows categorical color perception for surface colors of at least red, green, blue, yellow white, and black on which categorical color perception of the human visual characteristics is based.
The invention relates to the following three major technologies.
The first is a fluorescent lamp and a metal halide lamp for providing high-efficiency illuminating light source which allows high luminous brightness in mesopic vision and scotopic vision or in wide visual field, while ensuring such a level of color reproduction that allows categorical color perception for surface colors of at least red, green, blue, yellow, white and black.
The second is a fluorescent lamp and a metal halide lamp for providing illumination which has whiteness in the light color without causing sense of incongruity when used in conjunction with a conventional high temperature light source, while ensuring such a level of color reproduction that allows categorical color perception for surface colors of at least red, green, blue, yellow, white and black.
The third is a fluorescent lamp and a metal halide lamp for providing high-efficiency illumination which has light color equivalent to incandescent lamp color without causing sense of incongruity when used in conjunction with a conventional low color temperature light source, while ensuring such a level of color reproduction that allows categorical color perception for surface colors of at least red, green, blue, yellow, white and black.
In conventional lamps, spectral characteristic has been designed by evaluating the subtle color reproduction quality in terms of general color rendering index (Ra) with reference to a reference light source (black body radiation, reconstituted daylight radiator). In contrast, a Japanese patent application (Application No. JAP-HEI 7-242863(Sep. 21, 1995), PCT/jp96/02618 based on said Japanese application, discloses a method of optimizing the design of spectral characteristic by applying such human visual characteristics that human recognizes color roughly (namely categorical color perception).
This method made it possible to provide high-efficiency light sources while ensuring such a level of color reproduction that allows categorical color perception for surface colors of at least red, green, blue, yellow, white and black on which categorical color perception of the human visual characteristics is based. A point of achieving the light source realizing categorical color perception with high-efficiency is to concentrate the wavelength of light into wavelength bands mainly of green and red. Such a light source will be called new high-efficiency light source hereinafter.
The new high-efficiency light source which is designed with preference placed on the light emission efficiency while satisfying the minimum requirement of color reproduction is often used for exterior lighting, load lighting, street lighting, etc. This is because exterior, road, street, etc. does not require high fidelity quality color reproduction which is required for interior lighting, with emphasis placed on the luminous efficacy of the light source.
And another point to realizing such new high-efficiency light source is to set the deviation from Planckian locus (Duv) to be 0 or positive on uv chromaticity coordinates.
The range where deviation from Planckian locus (Duv) is 0 or higher is the region which allows categorical color perception of the basic colors with high efficiency. Therefore, the new high-efficiency light source takes positive values of Duv as far as categorical color reproduction of the basic colors can be maintained. Now a portion which has not been utilized in the conventional light sources other than the new high-efficiency light source, in the range of positive Duv values will be described in detail below.
As an international standard related to the classification of chromaticity of illuminating light sources for describing the light source colors, IEC (International Electrotechnical Commission) standard has been used. Various countries of the world also have their own standards. One of these is the chromaticity classification standard for fluorescent lamps specified in JIS (Japanese Industrial Standards) used in Japan.
The IEC standard determines light colors in terms of tolerance with reference to a central point which is preset in the vicinity of the Planckian locus, while the JIS defines upper and lower limitation lines in the vicinity of the Planckian locus and specifies the inner region of the limitation lines as the tolerable region.
Conventional lamps have been developed with care not to allow the emission to deviate upward from the Planckian locus (positive side of Duv), from the viewpoint of evaluating the color rendering performance of the prior art.
In actuality, however, width of the tolerable range is from 7.5 to 9.5 in terms of Duv in the vertical direction in the case of the IEC, and from 10 to 19 in the case of JIS, and therefore illuminating light sources having light colors in a range from 0 to 5 of Duv on the positive side have been used in the prior art.
As a standard for describing the applicable range of light source in terms of white color from a different point of view, there is the CIE standard for signal light color. According to this standard, the region on the positive side of Duv out of a narrow white color region specified along the Planckian locus has not been utilized as illuminating light source of white light.
An object of the invention is to improve the impression of brightness in mesopic vision and scotopic vision of the new high-efficiency light source. It is known that, under photopic vision condition where the illuminance is high, cone cells among the visual cells work, and under scotopic vision where the illuminance is low, rod cells among the visual cells work, while under mesopic vision where the illuminance is at the intermediate level between the above two, both cone cells and rod cells work. However, spectral characteristic of conventional illuminating light sources has been designed assuming photopic vision wherein cone cells work.
In a situation where the new high-efficiency light source is used, instead of a conventional light source designed for exact color reproduction, on the other hand, the illumination is designed with relatively low illuminance (scotopic vision, mesopic vision).
Therefore, it is the first object of the invention to design the spectral characteristic by placing emphasis on a condition of relatively low illuminance while taking into consideration the effect of the rod cells for the new high-efficiency light source.
Second object of the invention is to improve the impression of brightness in wide visual field of the new high-efficiency light source.
While illuminance and luminance are used as the photometric quantities of brightness, spectral characteristic of illuminance and luminance are based on the spectral characteristic of brightness measured in a visual angle of 2xc2x0 in the fovea centralis of the eye. However, because the eye receives light not only from a range limited around the fovea centralis but also from a wider visual field in the actual illumination environment, there have been such cases that actual impression of brightness is different from the illuminance, depending on the spectral distribution of the light source.
Thus the second object of the invention is to set such spectral characteristic of the new high-efficiency light source that improves the impression of brightness in a wide field of view which is felt when entering an actual illumination environment.
Third object of the invention is to improve the whiteness of light color of the new high-efficiency light source. The whiteness of the new high-efficiency light source is poor.
Hence the invention aims to improve the whiteness of the new high-efficiency light source as the third object.
Fourth object of the invention is to provide incandescent lamp type color image to the new high-efficiency light source.
That is, the invention aims to provide the impression of an incandescent lamp type color to the new high-efficiency light as a low color temperature light source.
An illuminating light source of the invention has the following means for improving the luminous brightness in mesopic vision and scotopic vision and improving the brightness in wide field view of the new high-efficiency light source.
One aspect is a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white, while improving the luminous efficiency in scotopic vision and mesopic vision or in a wide visual field, wherein dominant radiation is obtained from a phosphor which has peak emission wavelength in a wavelength region from 530 to 580 nm and a region from 600 to 650 nm, flux ratio of a phosphor having peak emission wavelength in a wavelength region from 420 to 530 nm is set to 4 to 40% of the total flux radiated in the dominant wavelength band, correlated color temperature of the lamp light color is set to 3500 K to ∞ and Duv (distance from perfect radiator locus on uv coordinates) is set within a range from 5 to 70.
Another aspect is a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white, while improving the luminous efficiency in scotopic vision and mesopic vision or in a wide visual field, wherein dominant radiation is obtained from a phosphor which has peak emission wavelength in a wavelength region from 530 to 580 nm and a region from 600 to 650 nm, flux ratio from a phosphor having peak emission wavelength in a wavelength region from 470 to 530 nm is set to 4 to 40% of the total flux radiated in the dominant wavelength band, correlated color temperature of the lamp light color is set to 3500 K to ∞ and Duv (distance from perfect radiator locus on uv coordinates) is set within a range from 5 to 70.
Yet another aspect is a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white, while improving the luminous efficiency in scotopic vision and mesopic vision or in a wide visual field, comprising phosphors having peak emission wavelengths in wavelength regions from 420 to 530 nm, 530 to 580 nm and 600 to 650 nm and light colors in a region of y less than xe2x88x920.43x+0.60, y greater than 0.64x+0.15 and x greater than 0.16 on the x-y chromaticity coordinate plane.
Still another aspect is a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white, while improving the luminous efficiency in scotopic vision and mesopic vision or in a wide visual field, comprising phosphors having peak emission wavelength in wavelength regions from 470 to 530 nm, 530 to 580 nm and 600to650 nm and light colors in a region-of y less than xe2x88x920.43x+0.60, y greater than 0.64x+0.15 and x greater than 0.16 on the x-y chromaticity coordinate plane.
Still yet another aspect is the fluorescent lamp of previously described, wherein the phosphor used to obtain the dominant radiation having peak emission wavelength in a wavelength band from 530 to 580 nm is a phosphor activated with terbium or terbium and cerium, a phosphor having peak emission wavelength in a wavelength band from 600 to 650 nm is a phosphor activated with europium or manganese, a phosphor having peak emission wavelength in a wavelength band from 420 to 530 nm and a phosphor having peak emission wavelength in a wavelength band from 470 to 530 nm are phosphors activated with europium or europium and manganese, or antimony or manganese, or antimony and manganese.
Another aspect is a fluorescent lamp, wherein phosphor having peak emission wavelength in wavelength regions from 530 to 580 nm and 600 to 650 nm comprises a single phosphor made of (Ce,Gd,Tb)(Mg,Mn)B5O10 and (Ce,Gd) (Mg,Mn)B5010.
The invention may also include a fluorescent lamp, wherein a phosphor having peak emission wavelength in a wavelength region from 420 to 530 nm and a phosphor having peak emission wavelength in a wavelength region from 470 to 530 nm are halophosphate phosphor.
Also included is a fluorescent lamp, wherein a phosphor having peak emission wavelength in wavelength region from 420 to 530 nm is BaMgAl10O17:Eu, (Sr,Ca,Ba)10(PO4)6Cl2:Eu or BaMgAl10O17:Eu,Mn.
Also included is a fluorescent lamp, wherein a phosphor having peak emission wavelength in wavelength region from 470 to 530 nm is Sr4Al14O25:Eu or Ce(Mg,Zn)Al11O19:Mn.
Another aspect is a fluorescent lamp, which includes a phosphor having peak emission wavelength in wavelength regions from 420 to 470 nm and a phosphor having peak emission wavelength in wavelength regions from 470 to 530 nm at the same time.
In addition, the invention includes a fluorescent lamp, wherein the phosphor having peak emission wavelength in wavelength regions from 420 to 470 nm and the phosphor having peak emission wavelength in wavelength regions from 470 to 530 nm are (Ba,Sr)MgAl10O17:Eu,Mn.
When the new high-efficiency light source is used in conjunction with the conventional high color temperature light source, the illuminating light source of the invention has the following means for improving the whiteness of the light color.
Also included is a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white, while improving the whiteness of the light color, wherein dominant radiation is obtained from a phosphor which has peak emission wavelengths in a wavelength region from 530 to 580 nm and a region from 600 to 650 nm, a phosphor which has peak emission wavelength in a wavelength region from at least 420 to 470 nm is included as sub-emission, correlated color temperature is set to 3500 K to ∞, Duv (distance from perfect radiator locus on uv coordinates) is set within an area of y less than xe2x88x920.43x+0.60 in the range from 5 to 70 on the x-y chromaticity coordinate plane.
Another aspect is a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white, while improving the whiteness of the light color, wherein dominant radiation is obtained from a phosphor which has peak emission wavelength in a wavelength region from 530 to 580 nm and a region from 600 to 650 nm, a phosphor which has peak emission wavelength in a wavelength region from at least 420 to 470 nm is included as sub-emission, and chromaticity points (x, y) are located in an area of y less than xe2x88x920.43x+0.60 within the region enclosed by a: (0.228, 0.351), b: (0.358, 0.551), c: (0.525, 0.440), d: (0.453, 0.440, e: (0.285, 0.332) on the x-y chromaticity coordinate plane.
Also included is a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white, while improving the whiteness of the light color, wherein dominant radiation is obtained from a phosphor which has peak emission wavelength in a wavelength region from 530 to 580 nm, and chromaticity points (x, y) are located in an area of y less than xe2x88x920.43x+0.60 within the region enclose by a: (0.228, 0.351), b: (0.358, 0.551), c: (0.525, 0.440), d: (0.453, 0.440, e: (0.285, 0.332) on the x-y chromaticity coordinate plane.
The present invention also includes a fluorescent lamp, wherein proportion of flux emitted by a phosphor which has peak emission wavelength in the sub-emission wavelength region from 420 to 470 nm and flux emitted by a phosphor which has peak emission wavelength in wavelength region from 530 to 580 nm is set to B:G with B being set within a range from 4 to 11% and G being set within a range from 96 to 89%.
Also included is a fluorescent lamp, wherein flux emitted by a phosphor which has peak emission wavelength in a range from 600 to 650 nm and the sum of flux emitted by a phosphor which has peak emission wavelength in a range from 420 to 470 nm and flux emitted by a phosphor which has peak emission wavelength in a range from 530 to 580 nm are blended in a ratio of R:(B+G) where R is set within a range from 0 to 28% and B+G is within a range from 100 to 72%.
Included also is a fluorescent lamp, wherein a phosphor activated with europium is used as the phosphor having peak emission wavelength in a range from 420 to 470 nm, a phosphor activated with terbium or terbium and cerium is used as the phosphor having peak emission wavelength in a region from 530 to 580 nm, and a phosphor activated with manganese or europium is used as the phosphor having peak emission wavelength in a range from 600 to 650 nm.
The invention also includes a fluorescent lamp, which is constituted from a phosphor activated with terbium having peak emission wavelength in a region from 530 to 580 nm and halophosphate phosphor.
The present invention also includes a fluorescent lamp, wherein phosphor having peak emission wavelength in wavelength regions from 530 to 580 nm and 600 to 650 nm comprises a single phosphor made of (Ce,Gd,Tb)(Mg,Mn)B5O10 and (Ce,Gd) (Mg,Mn)B5O10.
The present invention includes a fluorescent lamp, wherein a phosphor having peak emission wavelength in wavelength region from 420 to 470 nm is BaMgAl10O17:Eu, (Sr,Ca,Ba)10(PO4)6Cl2:Eu or BaMgAl10O17:Eu,Mn.
When the new high-efficiency light source is used in conjunction with the conventional low color temperature light source, the illuminating light source of the invention has the following means for improving the sense of incongruity of the light color as incandescent color.
The present invention also includes a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white, wherein dominant radiation is obtained from a phosphor which has peak emission wavelength in a wavelength region from 530 to 580 nm and a region from 600 to 650 nm, correlated color temperature is set to 1700 K to ∞, and the emission light color is set within a range where the region of Duv (distance from perfect radiator locus on uv coordinates) from 5 to 70 and the region of chromaticity point (x, y) inside quadratic curve of fx2+gy2+hxy+ix+jy+k=0 (f=0.6179, g=0.6179, h=xe2x88x920.7643, i=xe2x88x920.2205, j=xe2x88x920.1765, k=0.0829) overlap each other on the x-y chromaticity coordinate plane.
The present invention additionally includes a fluorescent lamp which ensures categorical color perception for surface colors of at least red, green, blue, yellow and white., wherein dominant radiation is obtained from a phosphor which has peak emission wavelength in a wavelength region from 530 to 580 nm and a region from 600 to 650 nm, the region of chromaticity point (x, y) is in a region which is the inside part of the quadratic curve of fx2+gy2+hxy+ix+jy+k=0 (f=0.6179, g=0.6179, h=xe2x88x920.7643, i=xe2x88x920.2205, j=xe2x88x920.1765, k=0.0829) other than the area defined by 1 to v range enclosed by line segments connecting the chromaticity points l: (0.4775, 0.4283), m: (0.4594, 0.3971), n: (0.4214, 0.3887), o: (0.4171, 0.3846), p: (0.3903, 0.3719), q: (0.3805, 0.3642), r:
(0.3656, 0.3905), s: (0.3938, 0.4097), t: (0.4021, 0.4076), u: (0.4341, 0.4233) and v: (0.4348, 0.4185) on the x-y chromaticity coordinate plane.
The present invention also includes a fluorescent lamp which obtains predominant radiation from a phosphor having peak emission wavelength in a wavelength region from 530 to 560 nm and a region from 600 to 650 nm, wherein proportion of flux emitted by a phosphor which has peak emission wavelength in the wavelength region from 530 to 560 nm and flux emitted by a phosphor which has peak emission wavelength in wavelength region from 600 to 650 nm is set to G:R (%) with G being set within a range from 70 to 59 and R being set within a range from 30 to 41.
The present invention includes a fluorescent lamp which obtains predominant radiation from a phosphor having peak emission wavelengths in a wavelength region from 530 to 560 nm and a region from 600 to 620 nm and sub-emission is obtained from a phosphor having peak emission wavelength in a wavelength region from 420 to 530 nm, wherein flux ratio (B+BG):G:R (%) of phosphors having peak emission wavelength in wavelength regions from 420 to 530 nm (B+BG), 530 to 560 nm (G) and 600 to 620 nm (R) is set so that B+BG is from 0 to 3, G is from 59 to 71 and R is from 41 to 26.
The present invention includes a fluorescent lamp, wherein a phosphor activated with terbium or terbium and cerium is used as the phosphor having peak emission wavelength in a region from 530 to 580 nm, and a phosphor activated with europium or manganese is used as the phosphor having peak emission wavelength in a range from 600 to 650 nm.
The present invention also includes a fluorescent lamp, wherein phosphor having peak emission wavelength in wavelength regions from 530 to 580 nm and 600 to 650 nm comprises a single phosphor made of (Ce,Gd,Tb)(Mg,Mn)B5O10 and (Ce,Gd) (Mg,Mn)B5O10.
When the invention is applied to a light source other than fluorescent lamp, the illuminating light source of the invention has the following means for solving problems.
The present invention also includes a fluorescent lamp which is used as exterior lighting, road lighting, street lighting, security lighting, car lights, tunnel lighting, public square lighting, warehouse lighting standby lighting or industrial lighting.
The present invention may also be a metal halide lamp which has light color and emission spectrum equivalent to those of the fluorescent lamps discussed above.
The present invention also includes a metal halide lamp which is used as exterior lighting, road lighting, street lighting, security lighting, car lights, tunnel lighting, public square lighting, warehouse lighting standby lighting or industrial lighting.